A Packet Data Convergence Protocol (PDCP) splitting technology is a technology in which a PDCP layer is used as an anchor, data packets on a bearer are split at a protocol layer below the PDCP layer, and the data packets are sent to a terminal by using different air interfaces.
In the technology, after data of a same terminal is processed at the PDCP layer, obtained PDCP data packets may be split to different network elements for processing and sent to the terminal. After receiving the data packets, the terminal aggregates the data packets at the PDCP layer. In the foregoing process, there is a difference between processing speeds of the different network elements, and a delay is generated during data interaction. Therefore, moments at which the split data packets arrive at the terminal are often different, and this may result in a packet loss.